Tri-Source Thermal Regime and Geothermal Controls in the Tengchong Recent Volcanic Hot Dry Rock System, SE Tibet

The Tengchong volcanic area， situated within the Mediterranean-Himalayan belt， holds substantial potential for Hot Dry Rock （HDR） geothermal resources. However， a systematic understanding of the heat source mechanisms and the relationship between deep thermal architecture and fault-controlled transport remain limited. This study set out to deconstruct the region's thermal regime by integrating systematic rock thermophysical measurements， steady-state temperature logging from deep boreholes， and 2D thermal-hydraulic （T-H） coupled numerical modeling. The results reveal a high geothermal gradient （40.6-42.2 °C/km） and terrestrial heat flow of 109.72 mW/m².A tri-source heat budget is identified， comprising anomalous mantle heat flow (53.70 mW/m²) linked to lithospheric thinning， elevated radiogenic heat production from Upper Cretaceous granitic basement (mean 7.46 μW/m³)， and residual magmatic heat (～21.42 mW/m²). T-H simulations further demonstrate that high-permeability faults serve as dominant conduits for buoyant hydrothermal convection， producing spatial decoupling between deep volcanic heat sources and surface geothermal manifestations. This study establishes a unified， multi-scale thermal architecture model， offering a quantitative benchmark for HDR resource assessment in complex volcanic and post-collisional extension zones.